package ling.in.day68.util;

import ling.in.day68.dao.EmpMapper;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

public class MyBatisUtils {
    private static SqlSessionFactory factory;
    private static final ThreadLocal<SqlSession>THREAD_LOCAL=new ThreadLocal<>();

    static {
        try {
            InputStream is= Resources.getResourceAsStream("mybatis-config.xml");
            factory=new SqlSessionFactoryBuilder().build(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

public static<T>T getMapper(Class<T>clazz){
    SqlSession session= MyBatisUtils.getSession();
    return session.getMapper(clazz);
}


    public static SqlSession getSession(){
        SqlSession session=THREAD_LOCAL.get();
        if(session==null) {
            session=factory.openSession();
            THREAD_LOCAL.set(session);
        }
        return session;
    }
    public static void close(SqlSession session){
        session.close();
        THREAD_LOCAL.remove();
    }
    public static void commit(){
        SqlSession session=getSession();
        session.commit();
        close(session);
    }
    public static void rollback(){
        SqlSession session=getSession();
        session.rollback();
        close(session);
    }
}
